An efficient, economical, and convenient method was developed for the preparation of 2-substituted (N, O, C) benzothiazoles from N'-substituted-N-(2-halophenyl)thioureas, O'-substituted-N-(2-halophenyl) carbamothioates, or N-(2-halophenyl) thioamides via a base-promoted cyclization in dioxane without any transition metal. A one-pot variant combining the synthesis of the thiourea and the cyclization was also demonstrated. High yields were obtained, and a variety of functional groups were tolerated under these conditions. Transition-metal-free, mild reactive conditions, wide application scope, and shorter reaction times make this method superior to the reported methods for the synthesis of 2-substituted benzothiazoles and suitable for combinatorial format.